This invention relates to optical-to-electrical and electrical-to-optical modules and more particularly to grounding and electrical interconnects in such modules.
In optical-to-electrical and electrical-to-optical (hereinafter xe2x80x9coptoelectricxe2x80x9d) modules used in the various communications fields, one of the most difficult problems that must be solved is the electrical interconnection of the various components and the shielding of the module to prevent radiation into or out of the module. Providing this efficient interconnection and shielding requires very precise assembly procedures. Here it will be understood by those skilled in the art that the term xe2x80x9clightxe2x80x9d, as used throughout this disclosure, is a generic term that includes any electromagnetic radiation that can be modulated and transmitted by optical fibers or other optical transmission lines.
Much of the optoelectric module fabrication difficulty and expense is due to mounting and shielding difficulties of optical components, such as lasers, light emitting diodes, photodiodes, etc. Generally, there are two types of lasers that are used in optoelectric modules, edge emitting lasers and surface emitting lasers. Edge emitting lasers emit light in a path parallel to the mounting surface while surface emitting lasers emit light perpendicular to the mounting surface. The light from either of the lasers must then be directed into an optical fiber for transmission to a remotely located light receiver (i.e., a photodiode or the like). Lens systems are used at both ends of the optical fiber to direct light from a light generating component into the optical fiber and to direct light from the optical fiber onto a light sensing component. The apparatus used to mount the optical components and the lens systems can have a substantial effect on the construction of the optical systems and the assembly procedures for the optical systems. Also, the mounting structure for the optical components and the lens system must be very rugged and stable so that alignment is not disturbed by use or temperature changes. Further, the entire module must be shielded from external signals and the like and to prevent radiation to other external devices or modules.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object the present invention to provide new and improved optical component mounting and interconnect apparatus.
Another object of the present invention is to provide new and improved optical component mounting and interconnect apparatus that is rugged and stable.
Another object of the present invention is to provide new and improved optical component mounting and interconnect apparatus that is shielded to prevent radiation into and/or out of the module.
And another object of the present invention is to provide new and improved optical component mounting and interconnect apparatus that improve the fabrication efficiency and manufacturing capabilities of optoelectric modules.
Still another object of the present invention is to provide new and improved optical component mounting and interconnect apparatus that allows the use of a variety of optical components and component materials.
Still another object of the present invention is to provide new and improved component mounting and interconnect apparatus that is designed to reduce outside interference with the desired signal.
Briefly, to achieve the desired objects of the present invention in accordance with a preferred embodiment thereof, provided is optoelectric mounting and interconnect apparatus.
The apparatus includes an elongated housing having one end designed to be engaged in receiving equipment and an optoelectric module mounted in the housing. The module includes a ferrule defining an axial opening extending along an optical axis and having first and second ends positioned along the optical axis. A lens assembly is engaged in the ferrule along the optical axis. The first end of the ferrule is formed to receive an optical fiber therein such that an end of the optical fiber is positioned along the optical axis and adjacent the lens assembly and light passing through the optical fiber is acted upon by the lens assembly. Since the module may be a transmitter or a receiver, the light may be traveling out of the fiber or into the fiber. An optoelectric device is affixed to the opposite end of the ferrule so that light traveling along the optical axis appears at the optoelectric device.
A printed circuit board is attached to the housing and electrically coupled to the optoelectric device in the optoelectric module. The printed circuit board has a plurality of external electrical connections adjacent an exposed end for communicating with external equipment and at least one ground or common potential connection.
A metal can is mounted on the opposite end of the housing so as to substantially surround and shield the optoelectric module and the printed circuit board. The metal can defines an opening for receiving external equipment therein in communication with the external electrical connections of the printed circuit board.
Because of the novel construction of the optoelectric connector, a variety of different embodiments are available with only minor modifications. Examples of such embodiments are: electrically connecting the metal can directly to the chassis (generally ground) of receiving equipment and connecting the internal components to a common potential or ground through internal circuitry; electrically connecting the metal can directly to the chassis (generally ground) of receiving equipment and connecting the internal components to the metal can through a conductive sleeve and housing; electrically separating the metal can from the chassis of receiving equipment and connecting it through a conducting sleeve and housing to the internal components, which are then connected to a common potential or ground through the internal circuitry; and combinations of the above. Each of the above embodiments can be used in different applications and depend upon the specific use and operation intended as well as the receiving equipment.